Having sex every one to two days during your fertile window gives you the best chance of getting pregnant. That fertile window is roughly six days long, ending on the day you ovulate. The American Society for Reproductive Medicine notes that couples who have intercourse at this frequency maximize their chances, and that having sex even more often than that does not lower your odds.
The Fertile Window Explained
Your fertile window exists because of a simple biological overlap: an egg survives about 12 to 24 hours after ovulation, but sperm can stay alive inside the cervix, uterus, and fallopian tubes for three to five days. That means sex in the days leading up to ovulation can still result in pregnancy, since sperm are already waiting when the egg is released.
The highest chances of conception come from sex in the three days before ovulation. Having intercourse two days before ovulation, for example, carries roughly a 26% chance of pregnancy in that cycle. By contrast, sex the day after ovulation drops the probability to around 1%. This is why timing matters more than almost any other factor. About 36 hours before ovulation, your body releases a surge of luteinizing hormone (LH), which is what at-home ovulation test kits detect. A positive result on one of those tests signals that your most fertile hours are approaching.
Daily vs. Every Other Day
One of the most common concerns is whether having sex every day depletes sperm. Sperm concentration, volume, and total motile count do decrease with back-to-back ejaculations. One older study found a nearly 60% drop in total motile sperm in a second ejaculate compared to the first. That sounds alarming, but it doesn’t necessarily translate to lower pregnancy rates.
In practice, cycle-by-cycle conception rates are similar whether couples have sex daily, every other day, or even every three days during the fertile window. The only scenario where success drops noticeably is when intercourse happens just once during that window. So if daily sex feels like pressure, every other day works just as well. The ASRM puts it plainly: the optimal frequency is whatever feels right for you and your partner, as long as it falls within those key days.
How to Identify Your Fertile Days
If tracking ovulation feels overwhelming, a straightforward approach is to have sex two to three times per week starting soon after your period ends. For most women with regular cycles, this naturally catches the fertile window without requiring any monitoring at all.
If you want more precision, ovulation predictor kits (OPKs) are widely available at pharmacies. They test your urine for the LH surge that precedes ovulation by about 36 hours. Once you get a positive result, having sex that day and the following day puts you right in the peak window. Other signs of approaching ovulation include changes in cervical mucus (it becomes clear, slippery, and stretchy, similar to raw egg whites) and a slight rise in basal body temperature, though the temperature shift confirms ovulation after the fact rather than predicting it.
How Age Affects Your Odds
Frequency recommendations stay the same regardless of age, but the per-cycle success rate changes significantly. At 35, you have roughly a 15% chance of conceiving in any given month. By 40, that drops to about 5% per month. These lower odds don’t mean you should have sex more often. They mean it may simply take more cycles to conceive, and that timing intercourse accurately within the fertile window becomes even more valuable.
For women under 35, most fertility specialists suggest trying for a full year before seeking evaluation. For women 35 and older, that timeline shortens to six months.
Things That Quietly Work Against You
A few common habits can undermine your efforts without you realizing it. Most commercial lubricants, and even saliva, slow sperm movement. If you need lubrication, look for products that are hydroxyethylcellulose-based, free of fragrances and parabens. These are specifically designed to mimic natural vaginal mucus and won’t interfere with sperm motility. Household oils like coconut oil are not a safe substitute.
You may also have heard that certain sex positions improve your chances, or that lying flat with your hips elevated after sex helps sperm reach the egg. Neither of these claims has scientific support. No particular position has been shown to increase conception rates, and there’s little evidence that staying still afterward makes a difference. The timing of intercourse relative to ovulation matters far more than anything you do during or after.
A Practical Weekly Plan
If you have regular cycles (roughly 26 to 32 days), here’s a simple framework. Start having sex every one to two days beginning around day 8 or 9 of your cycle (counting from the first day of your period). Continue through about day 16 to 18. This covers the most likely ovulation window for the majority of cycle lengths.
If your cycles are irregular, ovulation predictor kits become more useful because you can’t rely on calendar estimates alone. Begin testing a few days after your period ends and have sex every one to two days once you see the LH surge approaching. For couples who find scheduled sex stressful, simply maintaining a rhythm of two to three times per week throughout the month is a low-pressure alternative that still gives you solid odds each cycle.